Yes, you do need a good Real Estate attorney there in TX. I don't know what the law is in TX about statute of limitations, but you need to be careful to not let the matter lie too long, or you will lose your ability to recover the property. A deed conveyed by a person deemed mentally incapacitated is a void deed. Seek an attorney's advice and assistance right away.
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I agree that you need to quickly seek the advice of an attorney licensed in Texas if you want to preserve any claim that you may have. Each state has a different time period within which you may file a lawsuit for certain causes of action. The biggest and most immediate hurdle that your facts present is the amount of time that has lapsed since the transfer to the land developer took place. A local attorney can figure out if there is a potential claim and whether or not that claim is barred due to the amount of time that has passed.
If the 80 acre property is in Florida, you need to consult a Florida real estate attorney as soon as possible.
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